Substitutions work when you just don't have an ingredient, you want to use a cheaper ingredient or you want to make it more nutritious. I use all 3 reasons. Below is a list of things that I have found that you can use for substitutions. ( I actually use a ton more, but not all of mine are highly successful :-) )
Instead of Ricotta cheese (in lasagna) you can use: Cottage cheese, sour cream or yogurt.
Instead of 1 cup light cream (particularly for soup) you can use: 1 cup whole milk and 1 tablespoon butter.
Instead of 1 cup of melted choc. chips you can use: 6 tablespoons cocoa, 7 tablespoons sugar and 1/4 cup shortening.
Instead of 1 cup cake flour you can use: 7/8 cup all purpose flour sifted with 2 tablespoons cornstarch.
Instead of oil (in baking) you can use: applesauce, grated zucchini or yogurt. (This works with somethings better than others. I do this a lot, not because I don't have oil but for the nutritional value.)
Instead of 1 tsp. Baking Powder you can use: 1/4 tsp baking soda + 1/2 cup buttermilk or 1/4 tsp baking soda + 1/2 tsp cream of tartar.
Instead of Sour Cream you can use: Yogurt.
Instead of Cream, whipped, you can use: Chill a 13 oz. can of evaporated milk for 12 hours. Add 1 tbsp lemon juice. Whip until stiff.Instead of Egg (in baking) you can use: 1/2 tsp baking powder, 1 tbsp vinegar, and 1 tbsp liquid or 1 egg in every 3 can be replaced with 1 tbsp cornstarch or
Soften 1 tbsp unflavored gelatin in 3 tbsp cold water; add 3 tsp boiling water; cool and beat until frothy; add to recipe (reduce other liquid by 2 tbsp).
Instead of Mayonnaise you can use: Sour Cream, Yogurt or pureed Cottage Cheese.
Instead some of the flour in baking you can use: Oatmeal, Corn meal, Rice flour, Bean flour, Whole wheat flour or Rye flour. (This will often mess the texture up a little but it is fun to experiment with and get more nutritional food.)
What are some substitutions that you commonly use?
For lots more frugal tips visit Biblical Womanhood.